Abstract: A power working machine has a machine body, a drive source mounted on the machine body for driving a work implement connected to the machine body, and an operating handle mounted on the machine body for undergoing rotation relative to the machine body. A throttle lever is mounted on the operating handle for undergoing pivotal movement to adjust an output of the drive source. A lock mechanism is mounted on the operating handle for locking the operating handle at a preselected rotational angular position relative to the machine body. A lock cancellation lever is mounted on the operating handle for unlocking the lock mechanism to thereby permit rotational movement of the operating handle relative to the machine body. A stopper section is mounted on the operating handle for permitting operation of the lock mechanism while preventing pivotal movement of the throttle lever and for preventing operation of the lock mechanism while permitting pivotal movement of the throttle lever.

Abstract: A power working machine has a machine body, trimming blades attached to the machine body and drivable by a drive source, an operating handle rotatably mounted on the machine body, a throttle lever disposed on the operating handle, and a throttle lock lever disposed on the operating handle for disabling pivotal movement of the throttle lever. The operating handle has a lock mechanism for locking the operating handle at a rotational position relative to the machine body, and an operation lever for unlocking the lock mechanism to thereby permit rotational movement of the operating handle and, simultaneously with the unlocking of the lock mechanism, for placing the throttle lock lever in a locking position to disable pivotal movement of the throttle lever. The throttle lock lever has a lock portion for permitting pivotal movement of the throttle lever while simultaneously locking the operation lever of the operating handle.

Abstract: A portable working machine has a motive power source for producing a rotational motion, a cutting blade mounted to undergo linear reciprocating motion, and a reduction mechanism for reducing a speed of the rotational motion produced by the motive power source. A motion conversion mechanism converts the rotational motion reduced in speed by the reduction mechanism into a linear reciprocating motion of the cutting blade. A case accommodates therein the reduction mechanism and the motion conversion mechanism and has a lower surface. A cover member covers the lower surface of the case. The cover member has a first part connected to the lower surface of the case and a second part contiguous to the first part and extending to underlie a part of the lower surface of the case located below the reduction mechanism with a space defined between the part of the lower surface of the case and the second part of the cover member.

Abstract: A bush cutting machine including has an operation rod, a cutter blade mounted to the front end of the operation rod for undergoing rotation, and a prime mover mounted to the rear end of the operation rod for rotationally driving the cutter blade. A throttle lever is pivotally mounted with respect to the operation rod for controlling an opening degree of a throttle valve of the prime mover to adjust a rotational speed of the cutter blade. A brake unit stops rotation of the cutter blade. A link mechanism is disposed in close proximity to the prime mover and is actuated by operation of the throttle lever to adjust the degree of opening of the throttle valve of the prime mover and to release the brake unit from a braking condition.

Abstract: In a power working machine where output power of a drive source is adjustable by a throttle lever pivotally movable between a non-operating position and an operating position, an operating handle, generally in the shape of a closed loop, is rotatably mounted on a shaft section extending from a machine body. Throttle lock lever is provided on the operating handle for disabling the pivotal movement of the throttle lever when necessary. The operating handle includes a lock mechanism for locking the handle at a desired rotational position, and an operation lever for unlocking the lock mechanism to permit rotational movement of the handle and simultaneously locking the throttle lock lever. Simultaneously with the unlocking of the lock mechanism, the operation lever locks the throttle lever in the non-operating position.

Abstract: A power working machine has a machine body, a drive source mounted on the machine body for driving a work implement connected to the machine body, and an operating handle mounted on the machine body for undergoing rotation relative to the machine body. A throttle lever is mounted on the operating handle for undergoing pivotal movement to adjust an output of the drive source. A lock mechanism is mounted on the operating handle for locking the operating handle at a preselected rotational angular position relative to the machine body. A lock cancellation lever is mounted on the operating handle for unlocking the lock mechanism to thereby permit rotational movement of the operating handle relative to the machine body. A stopper section is mounted on the operating handle for permitting operation of the lock mechanism while preventing pivotal movement of the throttle lever and for preventing operation of the lock mechanism while permitting pivotal movement of the throttle lever.

Abstract: A portable working machine includes a case in which a reduction mechanism for reducing speed of a rotational motion produced by an engine and a motion conversion mechanism for converting the rotational motion with reduced speed into a linear reciprocating motion of a cutting blade are accommodated. A cover member is disposed below the case for covering a lower surface of the case. The cover member includes a front part connected to the lower surface of the case and a rear part extending to underlie a part of the lower surface of the case located below the reduction mechanism with a gap or space defined therebetween. An impact-absorbing member of elastic material is disposed within the space for absorbing a force or impact applied to the rear part of the cover member.

Abstract: A bush cutting machine has a relay member mounted to undergo movement by actuation of a throttle lever to adjust the opening degree of a throttle valve and to release a brake unit from a braking condition. A first wire has first and second ends each connected to a respective one of the throttle lever and a first portion of the relay member so that pivotal movement of the throttle lever pulls the second end of the first wire in a pulling direction from a standby condition to an operative condition. A first end of each of second and third wires is connected to a respective one of the throttle valve and the brake unit.

Abstract: A bush cutting machine including an engine for rotatably driving a cutter blade, a throttle lever for adjusting a throttle of the engine, and a brake unit for stopping rotation of the cutter blade. By operating only the throttle lever, both releasing of the brake unit from a braking condition and adjusting the opening degree of the throttle can be achieved.

Abstract: An operational lever for a bush cutter includes a handle housed in a handle case, a throttle lever pivotally mounted to the handle, and a lock lever pivotally mounted to the handle. The operational lever further includes a torsional coil spring which exerts a resilient force on the lock lever. The lock lever is pivoted from an initial position to a pivoted position by an operator's palm. The throttle lever is then pivoted to a half-pivoted position by operator's fingers. When the palm is moved a small distance away from the handle case with the throttle lever held in the half-pivoted position, the lock lever is pivoted back towards the initial position by a resilient force of the spring. This causes a curved surface of a side protrusion portion of the lock lever to engage or abut on a side of a protrusion portion of the throttle lever.

Abstract: A bush cutting machine including an automatic braking mechanism having a brake drum formed integrally with a clutch case which houses a centrifugal clutch. When the number of rotations of a clutch drum decreases, at least two braking members press against the brake drum, whereby the clutch drum stops rotating, and a cutting blade also stops rotating automatically.

Abstract: An operational lever for a bush cutter includes a handle housed in a handle case, a throttle lever pivotally mounted to the handle, and a lock lever pivotally mounted to the handle. The operational lever further includes a torsional coil spring which exerts a resilient force on the lock lever. The lock lever is pivoted from an initial position to a pivoted position by an operator's palm. The throttle lever is then pivoted to a half-pivoted position by operator's fingers. When the palm is moved a small distance away from the handle case with the throttle lever held in the half-pivoted position, the lock lever is pivoted back towards the initial position by a resilient force of the spring. This causes a curved surface of a side protrusion portion of the lock lever to engage or abut on a side of a protrusion portion of the throttle lever.

Abstract: A bush cutting machine including an engine for rotatably driving a cutter blade, a throttle lever for adjusting a throttle of the engine, and a brake unit for stopping rotation of the cutter blade. By operating only the throttle lever, both releasing of the brake unit from a braking condition and adjusting the opening degree of the throttle can be achieved.

Abstract: A bush cutting machine including an automatic braking mechanism having a brake drum formed integrally with a clutch case which houses a centrifugal clutch. When the number of rotations of a clutch drum decreases, at least two braking members press against the brake drum, whereby the clutch drum stops rotating, and a cutting blade also stops rotating automatically.

Abstract: An operation-control lever unit for regulating engine power of an engine-powered working machine to control operation of a working tool includes a throttle-lever holding mechanism operative in response to pivotal movement of a lock lever in a locking direction to frictionally hold the throttle lever at a desired position. The throttle-lever holding mechanism includes a stationary cam formed integrally with the head portion of the operator's control handle for the machine, a movable cam on the lock lever and cooperating with the stationary cam to displace the lock lever along a support shaft in a direction away from the stationary cam, and a resilient member disposed behind the movable cam and resiliently urging the movable cam toward the stationary cam.

Abstract: An operation control lever unit for regulating power of an engine of an engine-powered working machine has a handle case attached to a support rod connected at one end to the engine and at the other end to a working tool, a throttle lever pivotally mounted to the handle case for controlling a throttle mechanism to regulate the engine speed, and a brake release lever pivotally mounted to the handle case in diametrically opposite relation to the throttle lever for releasing a brake mechanism associated with the engine. This arrangement enables the operator to manipulate the throttle lever using at least one finger excluding the thumb of its one hand and to depress the brake release lever with a palm of the same hand while maintaining a grip on the handle case.

Abstract: A crawler belt vehicle comprises a chassis, a pair of first wheels mounted on the chassis, a pair of second wheels mounted on the chassis, a pair of crawler belts each trained around the first pair of wheels and the second pair of wheels, and a pair of equalizers each for pressing one of the crawler belts against a ground. Each of the crawler belts has low-friction members spaced-apart from each other in a longitudinal direction of the crawler belt. Each of the equalizers has a leaf spring having a first end connected to the chassis and a second end opposite the first end, and a slider supported on the second end of the leaf spring for undergoing pivotal movement about an axis extending in the longitudinal direction of the crawler belt for pressing the crawler belt against the ground by the resiliency of the leaf spring.

Abstract: A bush cutting machine comprises a clutch case attached to a front part of an engine, an operation rod extending forwardly from the clutch case and having a brake lever, a cutting blade provided at a distal end of the operation rod, and a transmission shaft passing through the operation rod for transmitting drive power to the cutting blade. A brake drum is housed in the clutch case for braking the rotation of the cutting blade. A brake arm is swingably attached to a front wall of the clutch case closely to the brake drum. The brake arm carries at one end thereof a brake shoe for press contacting an outer peripheral surface of the brake drum. A brake wire is mounted between the brake lever and brake arm. The brake wire is disposed to extend along either external surface of the operation rod.

Abstract: An operation lever unit includes an operation handle attached to an operating rod of an engine-powered portable working machine. The operation handle is equipped with a throttle lever for regulating the power of an engine, a lock lever for holding the throttle lever in a desired position, and a secondary throttle adjustment lever for achieving a fine adjustment of the position of the throttle lever. To hold the throttle lever in the desired position, the throttle lever is forced against a portion of the operation handle by the action of a thrust cam mechanism disposed between the throttle lever and the lock lever. For achieving the fine adjustment of the throttle lever position, the secondary throttle adjustment lever is forced by a thumb of the operator to forcibly turn the throttle lever against a frictional force acting between the throttle lever and the handle portion.

Abstract: A crawler belt vehicle comprises a chassis having a first end portion and a second end portion, first wheels mounted on the first end portion of the chassis for rotation, a swing arm having a front end and a rear end mounted on the second end portion of the chassis for undergoing pivotal movement relative to the chassis about a first axis, driving shafts mounted for rotation about a second axis and connected to the front end of the swing arm for undergoing pivotal movement therewith, and second wheels are mounted on the driving shafts for rotation therewith. Beam members are connected to the front end of the swing arm for undergoing pivotal movement therewith. Wheel axles are mounted on the beam members for rotation about a third axis and for undergoing pivotal movement with the beam members. Third wheels are mounted on the wheel axles for rotation therewith and are disposed between the first wheels and the second wheels.